The Mechanisms of Psychedelic Visionary Experiences: Hypotheses from Evolutionary Psychology

Abstract

Neuropharmacological effects of psychedelics have profound cognitive, emotional, and social effects that inspired the development of cultures and religions worldwide. Findings that psychedelics objectively and reliably produce mystical experiences press the question of the neuropharmacological mechanisms by which these highly significant experiences are produced by exogenous neurotransmitter analogs. Humans have a long evolutionary relationship with psychedelics, a consequence of psychedelics' selective effects for human cognitive abilities, exemplified in the information rich visionary experiences. Objective evidence that psychedelics produce classic mystical experiences, coupled with the finding that hallucinatory experiences can be induced by many non-drug mechanisms, illustrates the need for a common model of visionary effects. Several models implicate disturbances of normal regulatory processes in the brain as the underlying mechanisms responsible for the similarities of visionary experiences produced by psychedelic and other methods for altering consciousness. Similarities in psychedelic-induced visionary experiences and those produced by practices such as meditation and hypnosis and pathological conditions such as epilepsy indicate the need for a general model explaining visionary experiences. Common mechanisms underlying diverse alterations of consciousness involve the disruption of normal functions of the prefrontal cortex and default mode network (DMN). This interruption of ordinary control mechanisms allows for the release of thalamic and other lower brain discharges that stimulate a visual information representation system and release the effects of innate cognitive functions and operators. Converging forms of evidence support the hypothesis that the source of psychedelic experiences involves the emergence of these innate cognitive processes of lower brain systems, with visionary experiences resulting from the activation of innate processes based in the mirror neuron system (MNS).

Full text

HYPOTHESIS AND THEORY
published: 28 September 2017
doi: 10.3389/fnins.2017.00539
Frontiers in Neuroscience | www.frontiersin.org 1September 2017 | Volume 11 | Article 539
Edited by:
Andrew Robert Gallimore,
Okinawa Institute of Science and
Technology, Japan
Reviewed by:
Matt Joseph Rossano,
Southeastern Louisiana University,
United States
Eugene A. Kiyatkin,
National Institute on Drug Abuse,
United States
*Correspondence:
Michael J. Winkelman
michaeljwinkelman@gmail.com
Specialty section:
This article was submitted to
Neuropharmacology,
a section of the journal
Frontiers in Neuroscience
Received: 13 June 2017
Accepted: 15 September 2017
Published: 28 September 2017
Citation:
Winkelman MJ (2017) The
Mechanisms of Psychedelic Visionary
Experiences: Hypotheses from
Evolutionary Psychology.
Front. Neurosci. 11:539.
doi: 10.3389/fnins.2017.00539
The Mechanisms of Psychedelic
Visionary Experiences: Hypotheses
from Evolutionary Psychology
Michael J. Winkelman*
School of Human Evolution and Social Change, Arizona State University, Tempe, AZ, United States
Neuropharmacological effects of psychedelics have profound cognitive, emotional,
and social effects that inspired the development of cultures and religions worldwide.
Findings that psychedelics objectively and reliably produce mystical experiences press
the question of the neuropharmacological mechanisms by which these highly significant
experiences are produced by exogenous neurotransmitter analogs. Humans have
a long evolutionary relationship with psychedelics, a consequence of psychedelics’
selective effects for human cognitive abilities, exemplified in the information rich visionary
experiences. Objective evidence that psychedelics produce classic mystical experiences,
coupled with the finding that hallucinatory experiences can be induced by many
non-drug mechanisms, illustrates the need for a common model of visionary effects.
Several models implicate disturbances of normal regulatory processes in the brain
as the underlying mechanisms responsible for the similarities of visionary experiences
produced by psychedelic and other methods for altering consciousness. Similarities in
psychedelic-induced visionary experiences and those produced by practices such as
meditation and hypnosis and pathological conditions such as epilepsy indicate the need
for a general model explaining visionary experiences. Common mechanisms underlying
diverse alterations of consciousness involve the disruption of normal functions of the
prefrontal cortex and default mode network (DMN). This interruption of ordinary control
mechanisms allows for the release of thalamic and other lower brain discharges that
stimulate a visual information representation system and release the effects of innate
cognitive functions and operators. Converging forms of evidence support the hypothesis
that the source of psychedelic experiences involves the emergence of these innate
cognitive processes of lower brain systems, with visionary experiences resulting from
the activation of innate processes based in the mirror neuron system (MNS).
Keywords: psychedelic, cognition, mysticism, shaman, consciousness, neurophenomenology, mirror neuron
system
INTRODUCTION
Institutionalized use of psychedelics in religions of pre-modern societies worldwide reveal
the central roles of these substances in the evolution of spiritual experiences, cultures, and
religions (Schultes et al., 1992; Rätsch, 2005; Rush, 2013; Ellens, 2014; Winkelman, 2014;
Winkelman and Hoffman, 2015; Panda et al., 2016). The role of psychedelics in human
evolution is indicated by evidence that psychedelics bind to human serotonergic receptors

Winkelman Mechanisms of Psychedelic Visionary Experiences
with a higher affinity than they do to those receptor systems
in other primates (Pregenzer et al., 1997). The reasons for
the roles of psychedelics in cultural evolution are revealed
by neuropharmacological research on psychedelic effects on
brain processes. The interaction of psychedelics with the
innate structures of the human brain produces novel forms
of information and integrative cognitive processes (Carhart-
Harris et al., 2014b; Froese, 2015; Gallimore, 2015). This
suggests that psychedelic substances operated as environmental
factors selecting for an enhanced capacity for specific forms of
information processing.
The neuropharmacological dynamics of psychedelics are
central to understanding the nature of spiritual experiences.
Psychedelics are associated with pre-modern religious forms and
the early history of the current major world religions (Winkelman
and Hoffman, 2015). Furthermore, there is evidence established
by double blind clinical studies that spiritual experiences are
directly caused by neuropharmacological effects of psychedelic
substances (Griffiths et al., 2006, 2008, 2011). Why should the
pharmacological effects of psychedelics so consistently produce
such significant experiences? What neuropharmacological
mechanisms produce these powerful visionary
experiences?
While neuropharmacology is conventionally conceptualized
as the study of the effects of drugs on behavior, the ultimate goal
must also offer some explanation of how drugs have effects on
people’s experiences. Why do psychedelics produce the kinds of
experiences that lead to the foundation of cultures and religions?
How do the pharmacological effects so reliably and quickly
produce the kinds of experiences that mystical devotees spend
a lifetime pursuing for just a glimpse of these alleged eternal
truths?
Some might consider the answers to these questions to be
beyond the purview of neuropharmacology, perhaps best left
to philosophers. But a mature neuropharmacology ought to
be able to offer a cogent explanation of how it is that the
neurochemistry of an exogenous compound produces activity
and functional modifications in the brain that lead people across
time and place to report experiences of a profoundly spiritual
nature, often with great significance to the individual and even
society.
A neuropharmacological explanation of psychedelic effects
on human experience can be found in the approach of
neurophenomenology, “a research programme aimed at bridging
the explanatory gap between first-person subjective experience
and neurophysiological third-person data, through an embodied
and enactive approach to the biology of consciousness...
{N}europhenomenology is then viewed as a novel scientific
method building on a corpus of intersubjectively-invariant first-
person reports that may broaden the horizon of objective science”
(Khachouf et al., 2013, p. 1). We need to know what is being
experienced in order to identify what it is we are ultimately trying
to explain.
Neurophenomenology is an approach to the understanding
of the structure and content of phenomenal experience in
terms of principles operating at the neurological level (see
Laughlin et al., 1992; Varela, 1996; Thompson and Varela,
2001; Thompson, 2007). Or in other terms, the first person
perspectives of personal experience are explained by reference
to some homologous causal features identified by third person
perspectives on brain operation. If what people experience
ought to be explained in terms of pharmacological actions, then
psychedelics are an excellent example of this challenge presented
to neuropharmacology.
The experiences to be explained are not just some debatable
philosophical construct but an objective domain of experience
revealed by empirical evidence. A variety of research projects
provide converging findings that confirm the empirical nature
of the domains of altered states of consciousness (see Preller
and Vollenweider, 2016 for review). These domains of human
experience are assessed through psychometric instruments
such as: the Altered State of Consciousness Questionnaire
(Dittrich et al., 1985; Dittrich, 1998), later modified as the APZ-
OAV (Dittrich, 1998); the Phenomenology of Consciousness
Inventory (Pekala et al., 1986); the Hallucinogen Rating Scale
(Strassman et al., 1994; Riba et al., 2001); the Mysticism scale
(Hood et al., 2001); the Mystical Experiences Questionnaire
(MacLean et al., 2012; Barrett et al., 2015); and the Five
Dimensions of Altered States of Consciousness (5D-ASC;
Studerus et al., 2010). These studies provide empirical
evidence of common core dimensions to experiences of
pharmacologically and non-pharmacologically induced
alterations of consciousness.
If the ultimate goal neuropharmacology includes an
explanation of the nature of first-person psychedelic experiences
in terms of pharmacological, neurological and functional
brain mechanisms, what is this experience to be explained?
What is the nature of psychedelic experiences? There are
number forms of psychedelic experience, exemplified in
differences in mystical and shamanic psychedelic experiences
described below. The empirical data regarding these experiences
are startling and perhaps even confusing for the following
reasons:
1) Psychedelics reliably elicit experiences that are virtually
indistinguishable from mystical experiences induced through
prolonged austerities and disciplined contemplative practice
(Smith, 2000; Richards, 2016; Yaden et al., 2017); and
2) In contrast to the mystical features of psychedelic-induced
experiences, psychedelic use in pre-modern shamanic cultures
produced a distinctive worldview characterized by animism,
an experience of transforming into an animal, and the
perspective of entheogens, viewing these substances as
generating experiences of spiritual entities within the person
and environment (Dobkin de Rios, 1984; Winkelman, 2013b).
The differences in psychedelic-induced mystical and shamanic
experiences illustrate that while these substances reliably
produce certain kinds of experience, the forms of experience
may vary considerably—one agent, variable experiences.
Secondly, the similarity of psychedelic and non-psychedelic
mystical experiences suggests that the explanation of psychedelic
experiences is not through mechanisms unique to psychedelics,
but rather through shared mechanisms affected by non-drug
procedures.
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Winkelman Mechanisms of Psychedelic Visionary Experiences
Hypotheses
This leads to the central hypotheses of this paper:
1) The effects of psychedelics in producing visionary experiences
involve the same mechanisms elicited by other non-
drug mechanisms for altering consciousness and producing
visionary experience; and
2) These mechanisms involve a dis-inhibition of regulatory
mechanisms of the brain that releases a number of innate
modules, operators or intelligences, especially the mirror
neuron system (MNS).
Perhaps the most challenging fact that requires explanation in
neuropharmacological terms is how psychedelic-like visionary
experiences can also occur endogenously as a consequence
of a variety of ritual behaviors, physical activities, and
pathophysiological conditions (Winkelman, 2010a, 2013a).
What are the mechanisms by which pharmacological, mental,
behavioral and organic processes produce what appears to be the
same kind of experience?
Concepts of innate intelligences, operators and modules
identified by Gardner (1983,2000; also see d’Aquili and Newberg,
1999; Boyer, 2001; Ernandes, 2013) are used in the cognitive
science of religion to explain the universality of supernatural
beliefs and experiences. Supernatural experiences are also
central features of psychedelic visionary experiences in societies
worldwide. Parsimony suggests a common biological bases for
the supernatural beliefs found worldwide and the supernatural
beliefs stimulated by psychedelics.
Several models propose that similar mechanisms are shared
by many different alterations of consciousness (Mandell,
1980; Dietrich, 2003; Vaitl et al., 2005; Winkelman, 2011).
Common mechanisms that psychedelics share with other
alterations of consciousness involving effects that disable the
prefrontal cortex and default mode networks (DMNs). These
commonalities in the mechanisms by which psychedelics and
other processes alter consciousness provide a bridge between
neuronal and behavioral pharmacology. This leads to the
hypotheses regarding the common mechanisms by which
psychedelic and various procedures (meditation, hypnosis)
induced visionary experiences. This involves the consequences of
compromising the pre-frontal cortex and DMN, leading to the
release of innate modular brain operators and functions. One of
these, the MNS, is hypothesized to produce visionary experiences.
This system was central in the evolution of human cognitive
and symbolic capacities of imitation, mimesis, and symbolic
representation.
PSYCHEDELICS AS ELICITORS OF
SPIRITUAL EXPERIENCE
Some of the psychedelic-induced experiences that require
explanation in neurophenomenological terms are revealed
by Griffiths et al. (2006, 2008) who provided empirical
evidence that psilocybin induces a variety of features of
classic mystical experiences (Stace, 1960) under double-blind
conditions. Comparison with control periods showed psilocybin
produced significantly higher ratings on both introvertive and
extrovertive mystical experiences, an internal identification of
the divine within oneself, or an identification with an external
divinity, losing all sense of self-identity in a unity with the
cosmos. Psilocybin also induces a perception of sacredness and
a direct intuitive knowledge characterized as ineffable; a sense
of transcendence of time and space; experiences of oceanic
boundlessness; and positive mood, as evidenced by self-reports of
significantly higher levels of peace, harmony, joy, and happiness.
In addition, there were persisting effects of positive mood
changes and altruistic social behaviors noted by third-party
observers (Griffiths et al., 2008; MacLean et al., 2011). Follow-up
studies demonstrated persisting changes in the personality trait
of openness, as well as the personal and spiritual meaning that
participants gained from the experience (Griffiths et al., 2011).
The intrinsic mystical effects of psychedelics were further
confirmed in studies with LSD (Liechti et al., 2016). While the
authors reported that their LSD-induced mystical experiences
appeared to be less intense than those reported in the psilocybin
studies, they note that this may be the result of set and
setting differences. The likelihood of more spiritually inclined
participants in the Griffiths studies, along with their more
extensive preparation, may account for the higher levels of
psilocybin-induced mystical experiences (Polito et al., 2010; but
see Ray, 2010, since psilocybin’s active ingredient psilocin acts
differently than LSD at a variety of receptor sites).
Psychedelics induce experiences that alter the sense of
knowing through an experience of dissolution of the self
(Richards, 2016). The experiences induced by psychedelics
include the sense that knowledge is ineffable, beyond explanation,
yet somehow comprehensible through some direct unity with this
knowledge. The comparison of mystical experiences induced by
psychedelics with those induced by mental practice found the
former to be significantly more intensely mystical, having more
of a positive or existential impact on their life, and having given
the person an increased sense of purpose and spirituality (Yaden
et al., 2017). Psychedelics make easily accessible and more intense
what are generally rare mystical experiences.
Why do psychedelics evoke what are arguably among the most
important spiritual experiences of humanity? This answer lies
in the relationship of psychedelics to the evolution of human
cognitive and social capacities. This relationship derived from
the pharmacological effects on the brain of the substances in
the environment which were incorporated into religious rituals
across the early prehistory of humanity because of specific
adaptive effects enhancing certain aspects of human cognition
and social behavior.
Evolutionary Adaptations to Plant Toxins
Humans have a long-term symbiotic relationship with
psychedelics, derived from selective influences exercised by
these environmental factors (Sullivan et al., 2008); this effect
derives from the functions of plant substances as exogenous
analogous of human neurotransmitters (Sullivan and Hagen,
2002). Psychedelics affect a variety of neurotransmitters,
including serotonin, acetylcholine, norepinephrine, dopamine
and many others (Passie et al., 2008; Hintzen and Passie, 2010;
Ray, 2010).
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Winkelman Mechanisms of Psychedelic Visionary Experiences
Evidence for an influence of psychedelics on hominin
evolution is found in the much higher sensitivity of the
human serotonergic system for bonding with psychedelics
than is the case of great apes (Pregenzer et al., 1997).
Human and chimpanzee 5-HT1D receptor amino acid sequences
differ in ways that indicate molecular divergences in human
evolution. Human serotonergic systems (as compared to
chimpanzees) have a significantly greater binding with LSD
and the ergots metergoline and dihydroergotamine (Pregenzer
et al., 1997). These differences indicate that psychedelic plant
substances exercised selective effects that contributed to the
evolution of humanity’s neuropsychology. The inevitability of
psychedelic effects on human evolution is attested to by the
worldwide distribution and cultural use of psilocybin-containing
mushrooms (Guzman et al., 1998; Froese et al., 2016).
Evolutionary paradigms suggest that fitness benefits
accrued to our ancestors as a consequence of their ability
to utilize psychoactive substances to enhance the operation of
neurotransmitter systems. Sullivan and Hagen (2002) proposed
that the evidence for relationships of psychotropic plant
substances with humans’ cognitive capacities indicate that there
were selective benefits derived from substance use. The fitness
advantages that psychedelic substances offered impacted the
evolution of human consciousness and aspects of human social
psychology (Winkelman, 2013b). Smith (1999) proposed that
evolutionary influences of diverse classes of plant substances
include enhanced vigilance, pain management, increased mating
opportunities, reduction of apprehension and stress, feelings of
euphoria, increased endurance and self-confidence, enhanced
sensory and mental acuity, reduction of defensiveness, and
reduction of depression and self-defeating activities.
The effects of plant substances on the brain’s reward centers
display hallmark features of natural adaptations (Smith and
Tasnadi, 2007). These resulted from selective pressures for
human metabolic systems that were capable of using these
exogenous sources of neurotransmitter precursors that were
designed to function as toxins to deter consumption of the
plant. There was a positive selection for pituitary cyclase-
activating polypeptide precursor (PACAP), a uniquely human
feature that emerged after separation from our common
ancestor with chimpanzees (Wang et al., 2005; also see
Rockman et al., 2005). The PACAP precursor gene was a
consequence of positive selection for enhancing the biological
activity of neuropeptides, protecting them from enzymatic
degradation and increasing their affinity for receptor binding
(Wang et al., 2005). Sullivan et al. (2008) pointed out
that the mammalian xenobiotic-metabolizing cytochrome P450
provides evidence of a deep evolutionary history of adaptation
to plant toxins resulting in a positive selection for the
CYP2D enzyme that enables the body to metabolize plant
toxins.
Shamanism: The Ritual Context of
Selection for Psychedelic Uses
The selective influences of psychedelics on human adaptation
occurred within the context of social rituals. This fundamental
role of ritual reflects the social importance of collective rituals
in primates—communication for enhancing cooperation within
groups (see Laughlin and d’Aquili, 1974; d’Aquili et al., 1979)—
which was expanded during hominin evolution (Winkelman,
2009, 2015). Ritual behaviors provided the most significant
collective institutions of early modern human societies (Rossano,
2009, 2012, 2015). These ritual practices gave rise to the
practices of shamanism found in pre-modern societies worldwide
(Winkelman, 2002, 2010a,b; Rossano, 2011).
Shamanic ritual was the core area of social life in the selection
for enhancement of capacities stimulated by psychedelics. This
included the stimulation of ritual healing responses (Winkelman,
2009, 2010b), such as hypnotic susceptibility and placebo effects
(McClenon, 1997, 2002; Rossano, 2009, 2011). Furthermore,
there is abundant evidence of multiple therapeutic mechanisms
elicited by psychedelics (Winkelman and Roberts, 2007a,b).
Psychedelic substances enhanced the experiences at the core of
shamanic practices and extended the psychological, cognitive
and social potentials of ritual alterations of consciousness
(Winkelman, 2013b; also see Bousoa et al., 2015).
A central feature of shamanic ritual is divination, the
acquisition of information manifested in visionary experiences.
Ritual activities (fasting, drumming, dancing, chanting) produce
habituating effects on the brain’s information processing system
(Winkelman, 2010a). Profound alterations of the brain’s ordinary
routines results in a greater randomization of brain activity,
allowing for spontaneous synaptic plasticity that can reshape
network connectivity and enhance overall coordination of neural
activity (Froese, 2015); psychedelics strongly evidence such
effects (Carhart-Harris et al., 2014b; Gallimore, 2015).
Krippner (2000) characterized shamanic experiences as
involving processes of deciphering images to infer meaning,
engaging innate image-schemata to acquire information relevant
to survival decisions. Hominin evolution involved an expansion
of intentional ritualized alterations of consciousness that
enhanced access to these internal experiences, propelling the
emergence of the symbolic mind, and an acceleration of
cultural evolution (Winkelman, 2002, 2009). Human cognitive
evolution involved abilities to make symbolic interpretations of
spontaneous images, using information acquired from normally
unconscious processes for prediction of future conditions
and responding to those challenges. Psychedelic alterations of
consciousness enhance access to information that is normally
unconscious, making it available through the visual symbolic
processes that use image-schemas to integrate knowledge.
Another adaptive feature of psychedelic substances involves
their contributions to enhanced social cohesion. Psilocybin
produces a shift in emotional biases toward positive stimuli
(Kraehenmann et al., 2016), decreasing visual threat processing
by reducing the modulation caused by the top-down connections
from the amygdala to primary visual cortex. Psilocybin reduces
the role of the amygdala in tuning of visual regions in
the face of threats, creating an acute shift in emotional
valence toward an enhanced processing of stimuli with positive
valence. This decrease of top-down connectivity in visual threat
processing is accompanied by a shift in emotional biases toward
positive interpretations. Similar dynamics are produced with
LSD (Dolder et al., 2016; paraphrase p. 2638), which impairs
recognition of sad and fearful faces; increases feelings of
happiness, trust, closeness to others; produces enhanced explicit
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Winkelman Mechanisms of Psychedelic Visionary Experiences
and implicit emotional empathy; increases participants’ desire
to be with others; and increases prosocial behavior. Psychedelic
effects enhance the primary social functions of rituals by tuning
interpersonal dynamics.
Pre-modern use of psychedelics involved an entheogenic
view that these sacred plants contained spirit beings capable
of producing changes in self, knowledge, personal powers
and relations with others. Central to shamanic psychedelic
experiences are encounters with a variety of spiritual
entities, particularly animals, and the experience of a personal
transformation into an animal form. Cross-culturally (Dobkin
de Rios, 1984; also see Shanon, 2010; Winkelman, 2013b)
the consumption of psychedelic plants is believed to release
special powers inherent to these plants. Psychedelics are seen
as producing experiences of the supernatural, including the
signature experiences of altered consciousness in shamanism, the
separation of one’s soul or spirit from the body and its travel to
the supernatural world. The intimate relationships of psychedelic
plant use to shamanic rituals and spirit relations indicates the
likelihood that use of psychedelic substances was part of the
processes of selection for human cognitive sensitivities to engage
these types of beliefs.
DIS-INHIBITORY PROCESSES IN THE
BRAIN DURING ALTERED
CONSCIOUSNESS
The fundamental similarities of psychedelic-induced and
naturally-induced mystical experiences (Smith, 2000; Yaden
et al., 2017) support the classic perennialist view of fundamental
commonalities to mystical experiences across cultures and their
independence of the mode of induction. These parallels point to
the need for an explanation of the neuropharmacological effects
of psychedelics in relationship to the non-drug mechanisms
that elicit comparable experiences. Why do the same visionary
dynamics of psychedelic experiences emerge in other contexts
where drugs are not the causal factor?
The idea that diverse methods of altering consciousness
produce similar experiences through eliciting similar brain
responses has a long history. Mandell (1980) proposed a general
physiological mechanism underlying transcendent states that
is evoked by many different drugs, physiological conditions
and procedures (i.e., hypnosis, meditation) which result in the
loss of serotonin inhibition of the hippocampal cells. This
loss of inhibition leads to an increase in cell activity and
manifestation of hippocampal-septal slow-wave EEG activity
that projects a synchronous slow-wave pattern across the lobes
of the brain. Activities such as long-distance running, food
and water deprivation, sleep loss and auditory stimuli such as
drumming and chanting elicit a similar driving response in
the brain (see Winkelman, 2013a for review). Mandell (1980)
also proposed that the hippocampus is the focal point of the
mechanisms that reduce the inhibitory serotonin regulation of
temporal lobe limbic function, resulting in a reduction of the
gating of emotional responses and an enhancement of activity in
the dopaminergic circuitry. The loss of serotonin inhibition over
various brain regions results in hypersynchronous discharges
across the hippocampal-septal-reticular-raphe circuit.
This general dynamic of alteration of consciousness is typified
by psychedelics. The phasic effects of psychedelics first stimulate
and enhance serotonin; secondly, saturate and overload the
serotonin system; and thirdly, release the habitual serotonin
repression of the dopaminergic system (Passie et al., 2008; Previc,
2009). Psychedelics’ resistance to normal reuptake mechanisms
locks out serotonergic transmitter sites and saturates the
serotonergic system, habituating the receptors and reducing the
regulatory processes of the serotonergic system. This results in a
release of the dopamine system normally repressed by serotonin.
The reduction of serotonergic and noradrenergic modulation
(control) results in the ascendance of the dopaminergic and
acetylcholine systems that produce a variety of notable visual
syndromes, especially hallucinations and dreaming (Hobson,
2001; Previc, 2009).
Psychedelic interruption of cortico-striato-thalamo-cortical
loops that inhibit the lower brain structures’ sensory gating
systems (Vollenweider, 1998; Vollenweider and Geyer, 2001)
results in enhanced availability of information normally
repressed by these systems. Vollenweider (1998) attributed
the mechanisms of action of psychedelics to effects on the
frontal-subcortical circuits, principal organizational networks
involving neuronal linkages and feedback loops of the frontal
cortical areas with the thalamus. Psychedelic interruption of
serotonergic inhibition of thalamic screening results in a flood
of information that can overwhelm the frontal brain with
a variety of normally repressed sensations that enhance the
availability of information managed by these ancient levels of the
brain.
The alteration of consciousness through disruption of the
normal brain control activities can be achieved by diverse means,
including psychological, physical and physiological stimulation
and disease (Vaitl et al., 2005). Vaitl and colleagues attributed the
general causes of alterations of consciousness to compromised
brain structures, disconnectivity in brain dynamics between
distributed brain regions, or imbalances in neurochemical
and metabolic processes. Vaitl et al. (2005), noted that
interruptions, asynchrony and uncoupling in thalamic systems
produce various anomalies of consciousness. Many alterations
of consciousness involve temporally disconnected oscillatory
activity of the thalamocortical circuits or defective connectivity
between distributed brain regions. This disconnectivity results
in the emergence of activity in the ascending thalamocortical
systems, producing hallucinatory experiences as a result of
intrinsic brain activity, which is no longer as constrained in the
absence of sensory input.
The alteration of consciousness through disruption of normal
control processes was also proposed by Dietrich (2003), who
reviewed evidence reporting that the deregulation of higher
order functions of the prefrontal cortex was associated with
endurance running, dreaming, hypnosis, drug induced states,
and meditation. d’Aquili and Newberg (1999) proposed that
the properties of mystical experiences result from processes like
deregulation, a deafferentation of normal input, and a functional
blocking of input into a brain structure. Enhanced attentional
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Winkelman Mechanisms of Psychedelic Visionary Experiences
processes characteristic of meditation result in deafferentation
of input from other systems, such as the environment, that
would be distracting to highly focused attention. As a result
of deafferentation, certain neural structures gain independence
from normal input and instead start firing according to their own
internal logic or pattern.
Barrett and Griffiths (2017) reviewed research on the
similarities of meditation and psychedelics on brain systems, and
proposed that their similarities involve effects on key areas of the
DMN. These parallels in effects of psychedelics and meditation
on key brain areas support the idea of common mechanisms
underlying psychedelic-induced and other visionary experiences.
Psychedelic Disruption of the Default
Mode Network
A number of research projects beginning with Carhart-Harris
et al. (2012) reported psychedelic effects involving a disruption
of the DMN (see Table 1). The DMN involves a network of
regions that function as hubs for the structural and functional
connections that underlie a range of meta-cognitive processes
that are normally activated during an inward focus of attention
such as activities of introspection and daydreaming (Buckner
et al., 2008; Uddin et al., 2009; Scheibnera et al., 2017). These
forms of metacognition involve processes that underlie self-
consciousness, reflective self-awareness and self-representation,
as well as perceptions of social others. The DMN is also
active in mental time travel, which engages autobiographical
memory as a reflection on one’s personal past; and projects
one’s self into the future, with imagined possible outcomes.
Khachouf et al. (2013) noted that the varied phenomenal qualities
associated with the ordinary functioning of the DMN engage
in representations of scenarios different from what is actually
going on in the immediate environment, a simulation of possible
life circumstances; and that these imagined mental perspectives
are in reference to one’s self. These kinds of thought processes
might intuitively seem like the activities underlying psychedelic
experiences, but the effects of psychedelics disrupt these habitual
patterns of thought.
Raichle (2015) characterized the DMN as based in the medial
and lateral cortices of the parietal and temporal lobes, as well as
medial prefrontal cortex (mPFC). Its major subdivisions include
the ventral medial and dorsal medial regions of the prefrontal
cortex, as well as the posterior cingulate cortex (PCC; with
precuneus) and the lateral parietal cortex. The DMN primarily
involves connections among the thalamus, PCC and mPFC and
areas of the limbic system (parahippocampal cortex and the
hippocampus) that function as a network for information routing
and integration (Buckner et al., 2008). Raichle (2015) concluded
that the cortico-cortical axonal pathways involve a structural core
comprised of the posterior medial cortex and parietal cerebral
cortex, as well as the temporal and frontal modules that link all
major structural hubs of the brain through the posterior areas
of the DMN, which provide central functional integration of
the brain networks. The DMN is functionally and anatomically
connected with the thalamus and precuneus, a connectivity that
is crucial to consciousness (Cunningham et al., 2017).
TABLE 1 | Psychedelic effects on the PFC and DMN.
Study: Carhart-Harris
et al., 2012
Kometer
et al., 2015
Palhano-Fontes
et al., 2015
Carhart-Harris
et al., 2016
Substance: Psilocybin Psilocybin Ayahuasca LSD
PCC Activity Decrease Decrease Decreased Decrease
Connectivity Reduced DMN,
precuneus
Decrease vmPFC,
PH/RSC
*mPFC Activity Decrease Decreased Increase
Connectivity Decrease PCC Increased w/
caudate/
Inf. Front. gyrus
AG Activity Decrease Increase of vmPFC/
Connectivity Inf. Front. gyrus
*dmPFC Activity Decreased
Connectivity
TPJ
Activity
Connectivity
*LTC
Activity
Connectivity
ATP Activity
Connectivity
*HP Activity
Connectivity
PH Activity Decrease Increase
Connectivity Decreased RSC
Increase dorsal
mPFC
*RSC Activity Decrease Decrease Decrease PH/PCC
Connectivity
*pIPL Activity Decreased
PCC
Connectivity
*ACC Activity Decrease Decrease
Connectivity
*, PFC component; PCC, Posterior cingulate cortex; mPFC, Medial prefrontal cortex; AG,
Angular gyrus; dmPFC, Dorsal medial prefrontal cortex; TPJ, Temporoparietal junction;
LTC, Lateral temporal cortex; ATP, Anterior temporal pole; HP, Hippocampus; PHC,
Parahippocampus; RSC, Retrosplenial cortex; pIPL, Posterior inferior parietal lobe; ACC,
Anterior cingulate cortex.
Psychedelic stimulation of excitatory cortical neurons with
serotonin 2A receptors disrupts the normal rhythmic oscillations
of cortical neurons; this results in a decoupling between cells,
leading to an overall disorganization of cortical activity (Carhart-
Harris et al., 2014a). Psychedelics cause reduced activity in the
DMN’s hub structures, which leads to a reduction in oscillatory
activity and network integrity (Carhart-Harris et al., 2012, 2016;
Muthukumaraswamy et al., 2013; Palhano-Fontes et al., 2015;
see dos Santos et al., 2016 for review). The overall result is
reduced functional connectivity among areas of the DMN. In
particular, decreased integrity of the DMN was reflected by a
decreased functional connectivity between the parahippocampus
and retrosplenial cortex, the magnitude of which was strongly
correlated with self-report ratings of experiences of spiritual
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Winkelman Mechanisms of Psychedelic Visionary Experiences
experience and “ego-dissolution” (Kometer et al., 2013; Lebedev
et al., 2015; Carhart-Harris et al., 2016; Tagliazucchi et al., 2016).
Muthukumaraswamy et al. (2013) also found that psilocybin
caused a reduction in oscillatory activity and power in posterior
and frontal association cortices and the DMN. This results from
decreased functional coupling between the frontal cortex and
the medial temporal lobe components of the DMN, as well as
between the medial prefrontal cortex and the PCC.
A review (dos Santos et al., 2016) of 25 neuroimaging studies
of serotonergic psychedelics concluded that a wide range of
imaging studies show the excitatory effects of oral administration
of psychedelics such as mescaline, psilocybin, and ayahuasca.
There are effects in frontolateral/frontomedial cortex and medial
temporal lobe areas that are known for their central roles
in cognitive functioning, as well as self-awareness, emotional
processing and memory. The review also revealed a decrease in
functional connectivity between key hubs of the DMN as were
reported in many studies (i.e., Carhart-Harris et al., 2012, 2016;
Tagliazucchi et al., 2014, 2016; Lebedev et al., 2015; Palhano-
Fontes et al., 2015; Kaelen et al., 2016); most reported a reduction
in connectivity between the PCC and ACC.
There are some differences among the various studies of
psychedelic effects on the DMN, reflecting issues such as which
phase of the experience was studied (early, middle, vs. late),
and the specific drug and dosage levels used. dos Santos et al.
(2016), noted that some of these differences may be a result of the
time-scales associated with the measurements used in different
techniques; other differences may be due to yet-to-be-determined
differences in the effects from oral vs. intravenous modes of drug
administration. Studies on other 5HT2 psychedelic substances
generally confirm this general effect on the DMN. Palhano-
Fontes et al. (2015) found ayahuasca produced a significant
decrease in activity throughout most parts of the DMN, especially
in the hubs of the PCC, precuneus, and the mPFC. Ayahuasca
also reduced functional connectivity within the PCC/precuneus.
Psychedelic Induction of Bottom-Up
Information Transfer
In contrast to these acute effects of psychedelics in reducing
functional connectivity within the DMN, there is an increased
functional connectivity between normally disconnected brain
networks. Psilocybin enhances novel connections among brain
areas, manifested in increased connectivity between networks
(Roseman et al., 2014; Kuypers et al., 2016) and a wider range
of connectivity states (Tagliazucchi et al., 2014, 2016). Resting
state networks showed a decreased functional segregation under
psilocybin, forming especially stable functional connections
that are present only during the psychedelic state (Roseman
et al., 2014) and increasing communication across the entire
brain (Petri et al., 2014). Psilocybin produces many new
transient structures that are manifested in very strong, persistent
topologically long-range functional connections that increase
integration across cortical regions, resulting in an increased cross
modular connectivity that produces more intercommunicative,
less constrained, modes of brain function (Petri et al., 2014,
p. 7, 8).
A change from top-down to bottom-up dynamics in the
transfer of information under psychedelics is confirmed by
Alonso et al. (2015), who assessed changes in directionality of
information flow in the brain provoked by ayahuasca. Using
measures of transfer entropy that assessed nonlinear changes in
functional connectivity, they found significant changes in the
connectivity of brain oscillations, particularly a disruption in
the functional connectivity of brain oscillations that reflected
modifications in the normal coupling between anterior and
posterior areas of the brain. Their analyses of transfer entropy
found decreases in the influence of frontal brain areas over the
posterior areas, specifically in the central, parietal, and occipital
regions. In contrast, there were increases in the influence of
posterior regions on the frontal anterior brain regions. These
complementary changes, anterior-to-posterior transfer entropy
decreases, and their imbalance with the posterior-to-anterior
transfer entropy were correlated with the intensity of subjective
effects and degree of incapacitation reported by the participants.
Psychedelics reduced DMN integrity and caused disintegration
in normal system functions by reducing connectivity of the
frontal cortex with lower brain areas (Alonso et al., 2015). “These
results suggest that psychedelics induce a temporary disruption of
neural hierarchies by reducing top-down control and increasing
bottom-up information transfer in the human brain” (Alonso
et al., 2015, p. 1).
General effects of psychedelics involve the temporary
disruption of the normal neural hierarchy, replacing the normally
predominant top-down control of information transfer in the
brain with an increasingly bottom-up dynamic characterized by
an increased influence of posterior regions over frontal areas of
the brain (Riba et al., 2004). This decoupling of the frontal areas
with the medial lobes resulted in a disorganization of the high-
level networks responsible for large-scale brain network integrity,
resulting in increased flexibility of networks and a more open
communication among them. The decoupling between frontal
and medial temporal lobe structures permits a freer operation
of the latter, which is associated with more primary forms of
consciousness based in a somatic awareness and subjective feeling
states.
Effects of Other Alterations of
Consciousness on the DMN
The interruption of the normal patterns of the DMN by
psychedelics provides important information about the
mechanisms of their neuropharmacological action in producing
phenomenological experience, such as the relationship of
the decreased connectivity between the parahippocampus
and retrosplenial cortex in producing an experience of “ego-
dissolution” (Muthukumaraswamy et al., 2013; Carhart-Harris
et al., 2016). But these kinds of effects of reduced activity and
connectivity within the DMN are also found with a number of
non-pharmacological methods for altering consciousness. The
interruption of ordinary control processes of the brain, which is
caused by psychedelics, is also found with other consciousness
altering practices such as meditation, hypnosis, and epilepsy.
The commonalities involve compromising the integrity of the
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Winkelman Mechanisms of Psychedelic Visionary Experiences
DMN, including its connectivity with other areas of the brain,
especially the PFC. These similarities across methods for altering
consciousness lead to specific hypotheses regarding the common
mechanisms of visionary experiences found in association with
psychedelics, as well as mysticism and other alterations of
consciousness.
The major types of meditation techniques (Concentration,
Loving-Kindness, and Choiceless Awareness) used by
experienced meditators produce a relative deactivation in
the main nodes of the DMN (Brewera et al., 2011). In
all three mindfulness meditation conditions, key DMN
regions (PCC and mPFC) showed less activity in meditators
compared to the controls. Similar results were reported in
an electroencephalography (EEG) and functional magnetic
resonance imaging (fMRI) study (Panda et al., 2016) comparing
20 Raja Yoga expert meditators (“mental concentration”) with
a control group to examine differences in the DMN. Their
fMRI results showed that in comparison to the controls, the
meditators had significant reductions in activity and connectivity
of the DMN’s posterior cingulate hub, which was not as
strongly connected with other areas of the DMN. Another study
(Scheibnera et al., 2017) of mindful attention practices found
significantly less neural activation in two primary DMN hubs,
the mPFC and PCC, as well as reduction in activity in the left
temporoparietal junction. A meta-analysis (Fox et al., 2016) of 78
neuroimaging studies examining patterns of brain activation and
deactivation associated with different styles of meditation found
that focused attention meditation produced significant activation
in two DMN areas (PFC and ACC), as well as a deactivation
of two major DMN hubs, the PCC and the posterior inferior
parietal lobule.
Hypnosis also reduces levels of activity in the anterior areas
of the DMN (McGeown et al., 2009), with an association of the
depth of attentional absorption induced by hypnosis with the
degree of reduction of DMN activity (Deeley et al., 2012). High
(vs. low) hypnotizibility subjects had greater decreases in DMN
activity, particularly the dorsal ACC, and reduced connectivity of
the PCC with areas of the Executive Control Network (Jiang et al.,
2017).
The relevance of epileptic seizures to understanding
psychedelic action on the brain is highlighted by many reports
of ecstatic visionary experiences from people who appear to
suffer epileptic attacks (Danielson et al., 2011). A wide range
of brain abnormalities involving impairment of brain function
frequently produced hallucinatory, self-transcendent and
mystical experiences (Urgesi et al., 2010; Kastrup, 2017). A wide
range of neuroimaging and electrophysiological studies report
that epileptic seizures also impair the primary nodes of the
DMN, particularly the precuneus/PCC, the medial frontal cortex
and lateral parietal cortex, as well as the ACC (Danielson et al.,
2011), with long-lasting decreases in DMN activity during and
following seizures (complex partial, generalized tonic-clonic,
and absence seizures). These outcomes suggest that decreases in
DMN activity involve the inhibition of the subcortical arousal
systems, a “network inhibition hypothesis” that seizure-induced
inhibition of arousal systems causes deactivation in other cortical
areas. Since the thalamus is strongly involved in all three seizure
types (complex partial, generalized tonic-clonic, and absence
seizures), the involvement of corticothalamic networks is implied
(Danielson et al., 2011), and also implicated in psychedelic effects
(Vollenweider and Geyer, 2001).
While this relationship of brain function impairment to visual
experiences can be attributed to the effects of disruptions of
inhibitory neural processes, Kastrup (2017) proposed that there
are additional causal principles yet to be identified. Barrett and
Griffiths (2017) noted the parallels revealed by neuroscience
research in terms of the neural bases of psychedelic and
meditative effects on the DMN. They reviewed research that
supports the hypothesis that a key aspect of psychedelic and
meditation-induced visionary experiences are a consequence of
decreased activity and functional connectivity in the medial
nodes of the DMN (PCC and MPFC), regions known to mediate
aspects of self-referential processing that underlie mystical
experiences of unity. Barrett and Griffiths (2017, p. 30) point
to further similarities: “Decreased activity in the IPL (and
specifically in the angular gyrus), and decreased communication
between the IPL and other areas involved in maintaining a
sense of self (such as the PCC) are observed both in studies of
meditation and in studies of classic hallucinogens.”
The interruption of the DMN, particularly the PCC, by
meditation, hypnosis and epilepsy, point to the necessity of
explaining psychedelic effects in a context that provides a general
explanation of the alteration of consciousness. But what produces
this rich, intense, personal and sometimes overwhelming visual
imagery?
HYPOTHESES ON THE ORIGINS OF
VISIONARY EXPERIENCES: INNATE
MODULES AND OPERATORS
This need for a general explanation of psychedelic effects
that includes these other methods of altering consciousness
is emphasized by the fact that they are also associated with
vivid visionary and hallucinatory experiences. What produces
the resultant experiences? Destabilization of habitual cognitive
mechanisms (i.e., DMN) has the effect of reducing top-
down brain dynamics and facilitating a bottom-up information
transfer. This permits the emergence of more ancient cognitive
processing capacities of the brain, a release of innate modular
systems of knowing that provide the commonalities that
underlie these diverse methods for altering consciousness.
The general hypothesis proposed here is that the visionary
effects of psychedelics, as well as other mechanisms for
altering consciousness, involve the release of innate intelligences,
operators, and modules that provide the structure and content for
these experiences.
The hypothesis that innate operators can explain features
of psychedelic experiences is justified on several grounds: the
evidence for innate modular functions in the entoptic images
provoked by psychedelics and diverse conditions (Siegel, 1977);
the modular structure of the human brain (Gardner, 1983, 2000);
the explanations offered in the cognitive science of religion for
supernatural experiences and beliefs in terms of the operation
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Winkelman Mechanisms of Psychedelic Visionary Experiences
of innate modules (Boyer, 2001, 2017; Clements, 2017); and the
relationship of an innate operator, the MNS, to the DMN and the
expressive capacities of mimesis (Garrels, 2006, 2011).
Entoptic Forms as Innate Operators
The engagement of psychedelics with innate systems is
exemplified in their stimulation of entoptic forms. Evidence
that psychedelic substances stimulate the release of innate
cognitive forms originated in Kluver (1928) studies of the effects
of mescaline on subjective experiences. Reports of recurring
geometric patterns led to the concept of entoptic images,
visual experiences generated by mechanisms within the visual
system. Kluver (1928) noted the recurrence of specific patterns
that he labeled “form constants.” These were represented in
several principal types: basic geometric forms and patterns; a
lattice or grating, including honeycombs, checkerboards, and
cobwebs; tunnels, funnels, and cones; spirals; and more complex
phenomena based on combinations of these forms. Siegel (1977)
found that the modifications of these basic forms and their
transformation involved the inclusion within broader geometric
patterns through incorporating the elemental forms within the
borders of other figures; and repeated combinations of basic
forms and their incorporation into ornamental designs and
mosaics.
The biological bases for these form constants has been
evidenced in their manifestation under diverse circumstances,
not only a range of drugs, but also near-death experiences,
hypnagogic states, medical conditions, sensory deprivation
or overstimulation, flickering lights, and extensive chanting
or rhythmic drumming (Siegel, 1977). The widespread
manifestation of these visual elements under diverse
circumstances attests to the elicitation of these innate
mechanisms in producing these characteristic psychedelic
experiences.
Humans’ Innate Intelligences: Modules and
Operators
Evolutionary psychology (i.e., Barkow et al., 1992; Cummings
and Allen, 1998; Carruthers and Chamberlain, 2000; Crawford
and Krebs, 2008; Confer et al., 2010; Buss, 2015a,b) presents
models of the evolution of a modular structure to the human
brain that provide explanations of why humans so naturally
experience supernatural entities. Evolutionary approaches
propose a modularity of the human mind that resulted
from the ancient acquisition of a number of adaptive innate
capacities that have been called innate intelligences, modules
and operators, each one dedicated to different specific cognitive
functions (see Gardner, 1983, 2000; d’Aquili and Newberg,
1999; Ernandes, 2013). Ernandes distinguished cognitive
operators from cognitive modules, with modules involving
more specific functions and anatomical brain structures,
while cognitive operators involve generalized functions that
involve connections with many areas of the brain. The
concept of modules also reflects the isolated functioning of
process, while the concept of operators reflects the notion of
automatic action in response to the appropriate triggering
stimuli.
A range of findings support a view of the human mind
as functioning through an integrated assembly of many
functionally specialized modular psychological adaptations
that operate mostly independently and unconsciously.
Gardner’s (2000) criteria for innate intelligences include: their
isolated (dys)function because of brain damage; exceptional
manifestation in idiot savants and child prodigies; an
evolutionary plausibility; central core cognitive operations;
a facility for encoding in symbol systems; a developmental
history in their manifestation; and support from experimental
and psychometric studies. Cognitive functions that are
manifested cross-culturally point to their underlying
biological dynamics involving neurognostic structures, the
neurobiological structures of knowing that provide the
universal aspects of the human brain/mind (Laughlin et al.,
1992).
Gardner (2000; p. 57) characterize ten of these basic innate
intelligences as biopsychosocial potentials inherent to our
species:
1) an intrapersonal intelligence for looking in at one’s own mind
and the ability to use awareness of one’s own capacities to
regulate one’s emotional life and relations with others;
2) an interpersonal intelligence, a capacity to engage a “theory of
mind” to infer others’ mental processes;
3) a linguistic intelligence (actually involves several capacities);
4) a logical-mathematical reasoning capacity that manifests in
extreme forms in the idiot savants with superhuman math
processing capacities;
5) a bodily-kinesthetic intelligence manifested in mimesis;
6) a musical intelligence to create and perform with sound and
instruments;
7) a spatial intelligence for creating patterns in space;
8) a naturalist intelligence for species recognition and
classification of species;
9) a spiritual intelligence providing a desire to know about non-
material experiences and cosmic entities and engaging with
spiritual, noetic and transcendent experiences; and
10) an existential intelligence that provides an ability to reflect
cosmic issues.
It is apparent that not all of these modules are equally
elicited by psychedelics or other alterations of consciousness,
but many are. The features of these modules are prominently
displayed in shamanic psychedelic experiences characterized by
the entheogenic world view of human and animal-like spiritual
entities with human-like cognitive and social properties and
special powers derived from the psychedelic influences. Shamanic
experiences also engage the bodily-kinesthetic intelligence
manifested in dance and enactment; the naturalist intelligence
involving the use of animal species for personal identity
and power; and the use of musical intelligence, including
chanting and drumming. Contemporary DMT experiences
(Luke, 2011) emphasize spiritual entities that reflect the
operation of the interpersonal intelligence, as well as spatial
geometric visions, out-of-body experiences, mind-to-mind
communication, and concerns with spiritual and existential
matters.
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Winkelman Mechanisms of Psychedelic Visionary Experiences
Innate modules and operators are the result of adaptations
made to solve specific problems typical of the hunter-gatherer
lifestyle. Their manifestation under diverse influences reflects
the elicitation of such adaptive responses. These include
positive emotions such as happiness and bliss; although
negative emotions may be involved in mystical and psychedelic
experiences, they appear less central, perhaps because depression
is not an adaptive response. The innate modules typically
activated by psychedelics involve successful adaptations: agency
detection, theory of mind/mind reading, animal intelligences,
musical intelligence, mimetic enactment capacities, and others.
Ernandes proposes that while the frontal cortex becomes
involved in the control of many innate operators, they mostly
have their basis in the R-complex and its linkages with the
limbic system since they are widely distributed in reptiles and/or
mammals. This role of these ancient brain system attest to
these modules as involving ancient adaptations. Psychedelic
experiences should not be expected to manifest operators that
depend on the higher level cognitive integration provided by
the PFC or the self or autobiographical qualities maintained by
the DMN. Psychedelics do not elicit mathematical intelligence,
and certain language functions can be difficult if not impossible;
a semantic function might notably remain while speech
is generally compromised. In contrast Gardener’s operators
for intrapersonal, interpersonal, bodily-kinesthetic (mimetic),
musical, and naturalist (animal) intelligence are prominently
manifested in psychedelic experiences, especially in the form of
supernatural entities.
Innate Intelligences and Supernatural
Experiences
The idea that human beliefs in the spirit world result from
basic brain operators is fundamental to the main theoretical
perspectives in the cognitive science of religion (e.g., see Boyer,
2001, 2017; Ernandes, 2013; Clements, 2017). The human
tendency to perceive animate entities wherever we look reflects
the underlying roles of modular capacities. The ubiquitous
human tendency to posit supernatural beliefs is a consequence
of a Hyperactive Agent-Detection Device (HADD; Barrett,
2000), a tendency to perceive an active agent under ambiguous
conditions. A fundamental function of the HADD is the
attribution of the intentionality of an agent as a fundamental
cause of any phenomena. Ernandes (2013) notes the ubiquity
of this animistic response across animal kingdoms indicates the
basis of the HADD is in reptilian and limbic operators. This
agency operator or agent-detection function expanded across
mammalian evolution through natural selection to enhance the
capacity for detection of intruders and predators. This resulted in
adaptations for the over-detection of agency because it has few
costs in comparison to the high costs associated with the failure
to detect predators.
These adaptive assumptions of an “unseen other” were in the
case of humans augmented with other projective assumptions—
the social other, the dominant other, the all-seeing other, and
the mental states of these others. This “theory of mind” capacity
to infer the mental states and intentions of others is extended
in thinking about bodiless spirits. The significance of modules
and operators in the explanation of religious behavior involves
linking them together in ways that allows for the creation of a
general model of a relationship among the elements of reality,
particularly their temporal and causal relations, in order to
develop explanatory models of the universe (Ernandes, 2013).
This assumption of the operation of a causal operator contributes
a sense of an unseen causative agent to account for the events
perceived when the cause is unknown, providing a mechanism of
supersensible forces and powers to fulfill human needs.
This capacity to detect something was expanded in humans
through the modeling of the cognition of others via our own
experiences, projecting our own dynamics for the interpretation
of others. This engages an inevitable tendency to project our own
internal psychodynamics as the framework for the interpretation
of other’s internal dynamics, and the basis from which the
unknown becomes humanized with the projection of our own
self, social and emotional qualities. We then come to perceive the
world as human-like and project human-like capacities into the
world in order to understand it through inference. This capacity
to infer the mental contents of another’s mind has an identified
basis in an innate modular capacity expressed through the MNS.
The Mirror Neuron System
Mirror neurons are brain cells that have the property of being
activated when a person performs a particular motor movement,
as well as when a person observes another person engaging
in that same specific movement. In this respect the mirror
neurons function both motor and sensory neurons, reflecting a
common neural basis for both observation of and engagement in
intentional and goal directed actions. The activation of mirror
neurons by behaviors and images of behavior creates a shared
experience through a common neurological system for the
participant engaging in an action and an observer’s experience
of seeing that action performed (Garrels, 2006).
There are significant interactions between the MNS and
the mPFC node of the DMN in mentalizing and embodied
simulation processes (Molnar-Szakacs and Uddin, 2013). The
ACC provides an important locus for the interaction of the
DMN with the MNS (Uddin et al., 2007). Washington and
VanMeter (2015) characterized the ACC/mPFC connectivity—
the dorsal and ventral regions of the mPFC with the dorsal
and ventral areas of the ACC—as constituting the most anterior
area of functional connectivity within the DMN. The integrated
cognitive and emotional functions of the dorsal and ventral
ACC/mPFC and PCC make them the ideal components for
the operation of a “life simulator,” engaging past experiences
as a basis for exploration of anticipated social events and
future scenarios (Washington and VanMeter, 2015). The strong
connections of the ventral ACC to limbic structures (amygdala,
hippocampus), cortical areas that mediate limbic structures
(orbitofrontal cortex and anterior insula), and the periaqueductal
gray, nucleus accumbens, and hypothalamus give it a central role
in the assessment and mediation of emotionally salient stimuli
(Washington and VanMeter, 2015).
This DMN connection with the MNS is stimulated by
increased activation of right fronto-parietal regions, which
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Winkelman Mechanisms of Psychedelic Visionary Experiences
overlap with MNS areas involved in the mapping of the
actions of others via simulation within one’s own motor system
(Molnar-Szakacs and Uddin, 2013). The frontoparietal mirror-
neuron areas provide a bridge between conceptualization of
self and conceptualization of others through self-representation
functions that are derived from co-opting the MNS system used
to recognize the actions of others (Uddin et al., 2007). The
imagination of self-produced activities or other’s activities both
activate the midline and frontoparietal structures; this suggests
that imagination is the common representational domain for
both DMN areas (cortical midline structures) and the MNS
(Uddin et al., 2007, p. 156). The MNS appears to provide a
lower level physical representational system that has important
mental functions of imagination in social behavior, enabling
us to mentally project events and simulate various outcomes
instead of having to actually witness or participate in events.
A basic function of the MNS is the active creation of internal
representations of not only actions, but also the affects and
motivations of others (Newlin, 2009); this makes it a primary
candidate for the images experienced under psychedelic and
other influences.
An amodal representational and conceptual system underlies
the meaning of both language and images, a common system
of semantic representation for comprehension of events whether
the input modality is language (sentences) or images (pictures;
Jouena et al., 2015). Brain activity manifested in conjunction with
understanding sentences as well as pictures involves the same
distributed cortico-striatal network that “included the middle
and inferior frontal gyri, the parahippocampal-retrosplenial
complex, the anterior and middle temporal gyri, the inferior
parietal lobe in particular the temporo-parietal cortex [with]... a
multi-component network reaching into the temporal pole, the
ventral frontal pole and premotor cortex” (Jouena et al., 2015, p.
72). They note that this “meaning” network overlaps with major
areas of the DMN and involves areas of the brain recognized
for their role in “semantic memory, embodied simulation, and
visuo-spatial scene representation” (Jouena et al., 2015, p. 72).
This common system for understanding both verbal and visual
events relies on a common distributed network that integrates
perception, action and conceptual processing.
This form of visual thought is based in image schemas
representing the basic structures of sensorimotor experience
(Johnson, 1987), with the behavioral manifestations directly
implicating the MNS. These sensorimotor structures derive
from repeated patterns of interaction of the organism with
the environment that are encoded in the most basic structures
of the brain and body as external objects of perception. The
image schemas that develop in our direct engagement with the
world become the structures that represent our inner mental
life and thought, a common structure for our relationships with
the external world and our internal structures of experience.
These imagined motor actions engage the same networks as the
actual movements, providing a common basis for the interaction
with the world and the re-imaging of those experiences
symbolically.
The most fundamental schema for analogical transfer of
meaning across domains involves the body’s ability to act
(Newton, 1996). It is an innate neurologically based body schema
that provides a common basis of both somatic and symbolic
levels of reality, allowing for visual information, behavioral
information, and symbolic information to be manifested
through the same medium (Winkelman, 2010a). It is this
re-representation of information in different systems-visual,
somatic, and behavioral—that provides the basis for symbolic
thought that emerged first in the visual domain.
The functions of mirror neurons in representing visual
images of others’ behavior and our same behavior supports the
hypothesis that mirror neurons mediate not only the production
of internal visual representations, but visionary experiences as
well. This visionary component of psychedelic experience ought
to be measurable by the well-establish construct of Visionary
Restructuralization (Dittrich, 1998; Studerus et al., 2010).
Mimesis as the Origin of Human Thought
The innate operation of a human cognitive processes known
as mimesis is through the MNS (see Garrels, 2006, 2011 for
review). The social functions of the MNS as an innate operator
are illustrated by Ernandes (2013), who used MacLean’s (1990)
extensive study of ritualized behaviors to identify innate cognitive
and behavioral operators. The mimetic operator is an extension
of one of the most basic communicative operators, the isopraxic
operator, which stimulates members of a species to perform
the same actions that are observed in the behaviors of other
members of the group. In humans this isopraxic operator of
behavioral emulation of the “other” is extended in mimesis
(see Gardner, 2000 bodily-kinesthetic intelligence). The mimetic
operator engages bodily movements as symbolic communication
devices, enhancing group coordination by building on the most
basic animal display behaviors, repeating each other’s behavior.
This preverbal communication system, manifested in bodily
movements, facial expressions and gestures, is an innate system
that links the minds of human infants with their social world
from the beginning of life. Mimesis produces meaning through
metaphor, using gesture and imitation in an enactment that
involves a mapping of body actions onto an imagined context
(Newton, 1996). Body metaphors express meanings through the
ability to mediate between the sensory domains and the domains
of meaning through analogical reasoning processes involving the
body.
Imitation was a basis for human evolution and the
development of culture in early hominins, beginning with the
primordial roles of mimesis in human learning and shared
intersubjective experience (Donald, 1991, 2006). Donald (2006,
p. 16) proposed mimesis was at the basis of a co-evolution of
our capacities for cognition and culture, providing a “a single
neurocognitive adaptation...[for] mime, imitation, gesture, and
the rehearsal of skill.” This intuitive form of communication
provided by the MNS also facilitated interpretation of complex
social situations and attributing meaning to others through this
capacity to infer others’ thoughts, intentions and desires.
These expressive manifestations of mimesis in dance, music,
and ritual provided a publicly accessible system of meaning.
These expressive capacities of mimesis provided the basis for
the evolution of the symbolic human mind into what Donald
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Winkelman Mechanisms of Psychedelic Visionary Experiences
(1991) called mimetic culture and mythic culture. Winkelman
(2010a) has shown how this mimetic complex of dance, music,
drumming and rhythmic enactment was the context within
which the collective rituals of ancient hominins were transformed
into the visionary rituals of shamanism. Psychedelic plant use
enhanced the access to this visual system and its information
capacities.
The recognition of these visual experiences of psychedelics
as symbolic representations has a precedent in the concept
of presentational symbolism (see Langer, 1951; Hunt, 1995).
Presentational symbolism is an imagetic capacity that is
foundational to meaning-making, a symbolic representation
system that precedes and supports our rational, language
based consciousness (see Winkelman, 2010a for discussion).
This ancient mode of imaginal consciousness appears in
dreams and daydreaming, as well as shamanic visions, mystical
experiences, near-death experiences, out-of-body experiences,
and psychedelic visions (Horváth et al., 2017). These processes
may be released by a variety of mechanisms that cause disruptions
in filtering processes that normally repress these archaic forms of
cognition.
Horváth et al. (2017) proposed that these processes also
function constantly in our daily life, a kind of autonomic
cognitive act that produces conscious experiences and affect in
a synthesis of perception and thinking. Visionary experiences
express a personal affectivity and representational capacities that
directly present to the subject material that emerges from their
own deep personal affective layers of consciousness. Psychedelic-
induced visionary experiences involve the stimulation of
powerful manifestations of this latent human cognitive capacity
that is a background to all experience. When released by
psychedelics this visionary modality easily and effortlessly takes
dominance of our consciousness through an internal engagement
with deep narrative levels of the mind that present the significant
affective dynamics of life. Lohmar (2016; p. 20) noted that
this expressive system provides a medium for three forms of
material essential for the performance of thinking: the ability to
retain in mind an object; engender other cognitions regarding
this image object; and manipulate these to consider future
possibilities.
DISCUSSION: A
NEUROPHENOMENOLOGY OF
PSYCHEDELIC MYSTICAL EXPERIENCES
The similarity in phenomenal experiences produced by
psychedelics and other alterations of consciousness attest to
the necessity of a biological model of their causation. While
the direct evidence for the specifics of neuropharmacological
causation of phenomenal experience is limited, there are bases
for hypotheses about these underlying causal mechanisms.
Simultaneous assessment of specific mystical experiences and
brain connectivity dynamics awaits methodological advances, but
correlations of the various scales of mystical experience and ASC
with gross changes in brain connectivity during sessions suggests
the likely underlying neurological mechanisms producing the
phenomenal experiences. Given the limited studies examining
psychedelic neurophenomenological dynamics, brain imaging
studies of similar meditative experiences can also suggest
hypotheses regarding the mechanisms by which psychedelics
produce mystical experiences (see d’Aquili and Newberg, 1999,
2000).
Mystical effects induced by psychedelics are partly the
consequence of inhibiting the normal functions of the
DMN. Disruption of connections of the parahippocampus
with the retrosplenial cortex is directly implicated in the
experiences of ego dissolution and dissolution of self-other
boundaries characteristic of mystical experiences (Kometer
et al., 2013; Lebedev et al., 2015; Carhart-Harris et al., 2016;
Tagliazucchi et al., 2016). However, it is not merely the
absence of DMN integrity which produces these experiences.
These egoless experiences as reflected in the measure of
“oceanic boundlessness” are associated with alterations in the
frontolimbic-parieto-striatal network and positively correlated
with the cerebral glucose metabolism in various brain areas,
including DMN regions (ACC, HP, inferior parietal cortex),
and PFC areas (frontomedial superior, frontolateral, and left
inferolateral; Vollenweider and Geyer, 2001).
Disrupted self functions may also underlie experiences of
unity and a sense of connection with the universe made
possible by the absence of a separating sense of self. The
changes in experience of self and relationship to a spiritual
“other” typical of personalized theistic mystical experiences likely
involve consequences of this psychedelic induced disruption of
DMN self-related functions. The high importance of a social
“other” in some mystical experiences implicates the activation or
disinhibition of areas of the dorsal medial subsystem of the DMN
that manages social information.
Disruption of the DMN may also account for the
frequently reported sense of ineffability—the inability to
express the experience in words. The occurrence of increased
meaningfulness under LSD (Preller and Vollenweider, 2016)
is in notable contrast to the frequent difficulty of speech. I
hypothesize that speech production is compromised because
of the lack of connections with the neocortical components
involving the frontal lobe (Broca’s area), while the language
capacity for understanding meaning persists because of its lower
anatomical basis near the DMN component, the inferior parietal
lobule in the superior temporal gyrus (Wernicke’s area). This
dynamic may explain the highly meaningful yet ineffable aspects
of the experiences that are represented in a system of knowledge
long recognized in philosophy and psychology in concepts such
intuition, tacit and implicit knowledge.
Prominent features of mystical experiences involve happiness,
joy, and bliss. Psychedelics both stimulate limbic areas that
manage emotional information as well as compromise the
serotonergic repression of the emotional brain, resulting in the
release of normally repressed emotional dynamics. d’Aquili and
Newberg (1999, 2000) proposed that the positive emotional
experiences and profound quiescence of meditative practices
result from a deafferentation of limbic stimulation from the
peripheral parasympathetic system, combined with reverberating
parietal lobule connections with PFC circuits that result in
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Winkelman Mechanisms of Psychedelic Visionary Experiences
stimulation of both divisions of the Autonomic Nervous System
and enhanced connections of the sensory association areas with
the inferior parietal lobe, a key DMN area. Picard and Kurth
(2014) provide a further hypothesis in their findings that intense
feelings of bliss result from stimulation the anterior-dorsal insula.
The separation of the self from the body is a well-
known mystical experience that is prominent in shamanic and
psychedelic experiences; these experiences known as an out-
of-body experience (OBE), soul flight and astral projection,
involve a disintegration of the normal unity of the self, body
and one’s visual perspective of the world (Metzinger, 2009). OBE
experiences involve an inner focus of awareness experienced
as a separation of the self from the physical body, with the
self experiences dominated by an internally generated visual
field.
The neural correlates of these OBEs involve a disruption
of a specific DMN area, the temporo-parietal junction (TPJ),
which integrates bodily and sensory modalities (Lopez et al.,
2008). Shamanic ritual practices disrupt this integrative function
through the effects of excessive drumming and dancing
(Winkelman, 2010a). The effects of extensive exercise overwhelm
the vestibular system, resulting in habituation and a shutdown
of the TPJ and sensory system. TPJ habituation results in a loss
of functional connectivity with the motor and somatic functions
and a dis-engagement of the self-image and awareness from
the visual field and body. This allows for the experience of
movement independent of the physical body. This disembodied
conscious self which persists in the face of physical crisis provides
experiences generally interpreted as justifying beliefs in a soul,
spirits, and supernatural powers (Metzinger, 2009).
The importance of mental state and intentions on psychedelic
effects is recognized in the notion that set and setting are the most
important determinants of the specific qualities of psychedelic
experiences. Differences of mystical and shamanic psychedelic
experiences may reflect the shamanic practice of ingestion of
psychedelics is conjunction with fasting, prolonged periods of
dancing and extensive singing and chanting, factors which could
be expected to alter the effects of the psychedelics on the
brain.
Commonality and Diversity in Psychedelic
Effects
5-HT2a has been considered the primary neurotransmitter
system affected by psychedelics (Nichols, 2004, 2016; Hintzen
and Passie, 2010), but action on other serotonin receptors
and other receptor systems has also been established (Ray,
2010, 2012; Halbertstadt and Geyer, 2011). Additionally, LSD’s
hallucinogenic effect through binding with the 5-HT2A receptor
can only occur when there is dimerization with the mGlu2
receptor (Rivero-Müller et al., 2013, p. 69). Consequently,
5HT2A receptor agonism is a necessary but not sufficient
condition for psychedelic effects. Furthermore, there are diverse
effects at the same receptor by similar agonists, and agonist
action on the same receptor may activate different intercellular
signaling pathways as a consequence of receptor oligomerization
and receptor trafficking (Rivero-Müller et al., 2013).
Rolland et al. (2014) noted that hallucinations may be
induced by a variety pharmacological mechanisms, including
the hyperactivation of dopamine receptors, such as that caused
by psychostimulants; stimulation of serotonin 5HT2a receptors
targeted by psychedelics; and the blockage of glutamate NMDA
receptors caused by dissociative anesthetics. They proposed that
these different pharmacological systems might share common
neurobiological pathways involving integrated neurobiological
circuits that when compromised can produce hallucinations. And
they hypothesized that diverse mechanisms, including dopamine
and serotonin activation and NMDAR blockage, can disrupt the
thalamic gating functions and cortico-striato-thalamo-cortical
loops, resulting in a disorganization of the brains basic filtering
processes.
While many psychedelics may share common effects,
they also have distinctive effects, neurologically as well as
phenomenologically (see Ray, 2010, 2016). In assessing the
different profiles of neurotransmitter interactions by various
types of psychedelics, Ray (2016, p. 49) noted that “[m]ost of
the drugs studied interact with multiple receptors, and most
of the receptors studied interact with multiple drugs” This
leads Ray (2010, 2012) to challenge the dominant theory of
psychedelic action as being primarily mediated by effects at the
5HT2 receptors. Examination of the relative affinity of various
psychedelics for a wide range of receptors (Ray, 2010, p. 22/41)
found that “LSD has the strongest interaction collectively with
the five dopamine receptors... [and] DMT has the strongest
interaction with any single dopamine receptor.
Previc (2009) also proposes that diverse alterations of
consciousness are a function of the activation of the dopamine
system, which is directly stimulated by many different
neurotransmitters and drugs and indirectly through effects
on other neurotransmitter systems. Previc (2006, 2009) notes
that dopaminergic activation favors extrapersonal cognition over
body-based cognitive processes, enabling context independent
cognition that processes information about events distant in
space and time and cognition about occurrences other than
those in the immediate present, typified in the OBE. Previc
reviews evidence indicating a common underlying mechanisms
for diverse methods of altering consciousness involving a
disinhibition of dopaminergic extrapersonal brain systems,
particularly those in the ventral cortex and the limbic circuit.
Independent of the specific neurotransmitters involved, diverse
processes producing visionary experiences may share common
underlying mechanisms in a thalamic sensory overload, the
common pathway resulting in a disruption of cortico-subcortical
processing (Vollenweider, 2001).
This common pathway can carry a variety of different features
of experience produced by the distinctive qualities of the various
psychedelic substances. Ray (2012, 2016) proposes that the
diversity in the phenomenology of psychedelic experiences is a
consequence of the distinctly different neurotransmitter receptor
profiles that each substance engages. Each neurotransmitter
system (i.e., the various serotonin receptor subtypes, beta
receptors, dopamine, histamine-1, imidazoline-1, kappa, mu,
sigma, and cannabinoid receptors) elicits a specific profile of
effects that Ray calls a mental organ. Each psychedelic drug has
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Winkelman Mechanisms of Psychedelic Visionary Experiences
effects on a range of neurotransmitter systems that results in its
characteristic effects on neuronal activity and on consciousness.
CONCLUSIONS
Similarities in visionary experiences across diverse modes of
altering consciousness attest to a common mechanism released
by the interruption of the PFC and DMN. The disruption of
the top-down control of the brain normally mediated by the
functions of the PFC, together with the compromised self-
referencing processes of the DMN, leads to the emergence of
processes that are normally repressed/regulated lower level brain
systems These ancient brain systems are manifested as innate
intelligences, modules and operators. Various findings support
the hypothesis that one of these innate capacities, the mirror
neurons and their operation in the mimetic capacity, is at the
basis of psychedelic and other visionary experiences. This novel
hypothesis regarding the MSN as a mechanisms of psychedelic
visionary experiences is supported by evidence that psychedelics
elicit innate brain functions (entoptics), and the roles of the
MNS in the integration of visual experience and behavior and in
providing a common basis for self and other perceptions.
This ancient visual modality of information presentation
and knowing elicited by psychedelics has seldom been studied
scientifically because of its inaccessibility to intersubjective
examination. Unfortunately, no mechanism allows us to share
visual experiences to the same extent that words allow us to
share our thoughts. The neuropharmacological dynamics of
psychedelics powerfully and reliably elicit this mode of symbolic
operation, making this modality of consciousness directly and
intensely accessible. The repeatable effects of psychedelics in
producing such visions and mystical experiences make them
an unparalleled tool for the examination of the operation of
this cognitive-affective system that is an innate aspect of the
human brain-mind. Psychedelics consequently can serve as tools
to provoke and expose this system, facilitating the examination
of an area of human knowledge that has remained marginalized
because of its notoriously subjective qualities. Through the use
of psychedelics we can come to better understand the nature
of some of the ancient symbolic and conceptual capacities of
the human brain and the kind of experiences that generate the
human quest for transcendent knowledge and spirituality.
AUTHOR CONTRIBUTIONS
The author confirms being the sole contributor of this work and
approved it for publication.
ACKNOWLEDGMENTS
I thank Heather Hargraves, Irene De Caso, Andrew Gallimore,
and Ede Frecska for suggestions for improving the various
versions of this paper. Thanks also to Roland Griffiths and Albert
Garcia-Romeu for articles considered in writing this paper. I also
thank a reviewer for the very constructive suggestions that lead
to a substantial revision of the manuscript.
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Conflict of Interest Statement: The author declares that the research was
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